x86, paravirt: Replace GET_CR2_INTO_RCX with GET_CR2_INTO_RAX

GET_CR2_INTO_RCX is asinine: it is only used in one place, the actual
paravirt call returns the value in %rax, not %rcx; and the one place
that wants it wants the result in %r9.  We actually generate as a
result of this call:

       call ...
       movq %rax, %rcx
       xorq %rax, %rax		/* this value isn't even used... */
       movq %rcx, %r9

At least make the macro do what the paravirt call does, which is put
the value into %rax.

Nevermind the fact that the macro clobbers all the volatile registers.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1334794610-5546-4-git-send-email-hpa@zytor.com
Cc: Glauber de Oliveira Costa <glommer@parallels.com>
This commit is contained in:
H. Peter Anvin
2012-04-18 17:16:48 -07:00
committed by H. Peter Anvin
parent 84f4fc524e
commit ffc4bc9c6f
2 changed files with 5 additions and 7 deletions

View File

@@ -1023,10 +1023,8 @@ extern void default_banner(void);
call PARA_INDIRECT(pv_cpu_ops+PV_CPU_swapgs) \
)
#define GET_CR2_INTO_RCX \
call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2); \
movq %rax, %rcx; \
xorq %rax, %rax;
#define GET_CR2_INTO_RAX \
call PARA_INDIRECT(pv_mmu_ops+PV_MMU_read_cr2)
#define PARAVIRT_ADJUST_EXCEPTION_FRAME \
PARA_SITE(PARA_PATCH(pv_irq_ops, PV_IRQ_adjust_exception_frame), \